EasyX精准帧率控制打气球小游戏
🎆音乐分享
New Boy —— 房东的猫
之前都用Sleep（）来控制画面帧率，忽略了绘制画面的时间
如果绘制画面需要很长的时间，那么就不能忽略了。
并且Sleep（）函数也不是特别准确，那么就要精准控制帧率了
🚥🚥🚥🚥🚥🚥
开始时间 结束时间 频率F
LARGE_INTEGER startCount,endCount,F;获取计数器累加频率
QueryPerformanceFrequency(&F);获取当前的计数值
QueryPerformanceCounter(&startCount);//获取起始计数，并保存在startCount里面获取终止计数
QueryPerformanceCounter(&endCount);计算时差
long long elapse=(endCount.QuadPart-startCount.QuadPart)*1000000/F.QuadPart;//根据LARGE_INTEGER的定义，elapse必须是long long 类型的查询是否超时
while (elapse < 1000000 / 60){//最长等待时间为60帧每秒Sleep(1);//先休眠1ms，防止CPU使用率过高QueryPerformanceCounter(&endCount);elapse = (endCount.QuadPart - startCount.QuadPart) * 1000000 / F.QuadPart;}这时候如果执行代码会发现，虽然我们指定了Sleep(1),但是还是休眠了15ms
这是因为 
要解决这个问题，就要加上
timeBeginPeriod(1);//改变定时器时钟分辨率为1mstimeEndPeriod(1);这里如果运行的话会报错，因为
timeBeginPeriod()和 timeEndPeriod()的实现在 库winmm.lib中
解决方法如下
把winmm.lib添加到附加依赖项中
当然，绘制画面也得加上下面的函数
BeginBatchDraw();
EndBatchDraw();🚥🚥🚥🚥🚥🚥
下面咱们来看一个打气球小游戏，把上面的帧率控制代码进行实操
//看着气球在画面中是分散的，其实可以把他们想象成是在一个数组里面的，然后进行操作
#include<easyx.h>
#include<stdio.h>
#include<math.h>#define WIDTH 800//窗体宽度
#define HEIGHT 600//窗体高度
#define NUM 5//窗体中的气球数量
#define RADIUS 30//气球半径//保存气球的各项数据
typedef struct {int x;int y;int r;//半径int v;//速度COLORREF color;
}balloon;//生成气球，并初始化
balloon generateBalloon()//因为arrBalloons[]是balloon类型的,所以generateBalloon()也应该是balloon类型的
{balloon b;int m, n;m = 100;n = 700;b.x = rand() % (n - m + 1) + m;b.y = HEIGHT;b.r = RADIUS;m = 1;n = 3;b.v = rand() % (n - m + 1) + m;b.color = RGB(rand() % 256, rand() % 256, rand() % 256);return b;
}int main()
{initgraph(WIDTH, HEIGHT);setbkcolor(WHITE);cleardevice();balloon arrBalloons[NUM];//保存目前窗体出现的气球数量for (int i = 0; i < NUM; i++)//给每一个气球赋值(大小，颜色){arrBalloons[i] = generateBalloon();}int current = NUM;//当前出现的气球数量int mouseX = 0, mouseY = 0;//鼠标位置timeBeginPeriod(1);LARGE_INTEGER startCount, endCount, F;QueryPerformanceFrequency(&F);BeginBatchDraw();while (1){QueryPerformanceCounter(&startCount);cleardevice();for (int i = 0; i < NUM; i++)//绘制气球{setfillcolor(arrBalloons[i].color);solidcircle(arrBalloons[i].x, arrBalloons[i].y, arrBalloons[i].r);}for (int i = 0; i < NUM; i++)//移动气球{arrBalloons[i].y -= arrBalloons[i].v;}int i = 0;while (i < current){int y = arrBalloons[i].y;if (y < -RADIUS)//气球飞出窗体{for (int j = i; j < current - 1; j++)//删除飞出的气球{arrBalloons[j] = arrBalloons[j + 1];}current--;}else{i++;}}if (current < NUM)//新增气球{arrBalloons[current] = generateBalloon();current++;}//绘制准心setlinecolor(RGB(237, 178, 29));setlinestyle(PS_SOLID, 3);circle(mouseX, mouseY, 20);line(mouseX - 20, mouseY, mouseX + 20, mouseY);//准心使用了mouseX,mouseY，便于准心可以与鼠标指针一起移动line(mouseX, mouseY - 20, mouseX, mouseY + 20);QueryPerformanceCounter(&endCount);long long elapse = (endCount.QuadPart - startCount.QuadPart) * 1000000 / F.QuadPart;while (elapse < 1000000 / 60)//最长等待时间为60帧每秒{Sleep(1);ExMessage msg;bool isOK = peekmessage(&msg, EX_MOUSE);if (isOK = true){if (msg.message == WM_MOUSEMOVE)//鼠标移动消息{ //更新鼠标位置mouseX = msg.x;mouseY = msg.y;}else if (msg.message == WM_LBUTTONDOWN)//鼠标点击消息{int i = 0;while (i < current){int ballX = arrBalloons[i].x;int ballY = arrBalloons[i].y;int distance = (int)sqrt(pow(ballY - msg.y, 2) + pow(ballX - msg.x, 2));if (distance < RADIUS)//如果点击到了气球，就把气球删除{for (int j = i; j < current - 1; j++){arrBalloons[j] = arrBalloons[j + 1];}current--;}else{i++;}}}}QueryPerformanceCounter(&endCount);elapse = (endCount.QuadPart - startCount.QuadPart) * 1000000 / F.QuadPart;}FlushBatchDraw();}EndBatchDraw();timeEndPeriod(1);closegraph();return 0;
}
//看着气球在画面中是分散的，其实可以把他们想象成是在一个数组里面的，然后进行操作Code over！